The present invention relates to braking correctors and, more particularly, to such correctors governed by the height of a vehicle.
It is known that it is desirable to connect such a braking corrector directly to the suspension of a vehicle, in order to vary the braking of the wheels of a vehicle as a function of its height which is itself usually a function of its load.
Such correctors are well known in the art of braking and typically comprise a body, in which is slideably mounted at least one piston controlled by an actuating rod and arranged so as to interact with at least one valve element in order to control at least one brake-fluid passage between at least one inlet and at least one outlet of the corrector, the corrector possessing a sensor detecting the height of the vehicle and formed from a lever, the pivot of which is stationary relative to the body of the corrector and one end of which is connected to an unsuspended part of the vehicle, the distance between this end and the pivot defining a first lever arm, and the lever, which actuates the actuating rod at a distance from the pivot, defining a second lever arm.
Likewise conventionally, the connections between the lever and the actuating rod or the unsuspended part of the vehicle are made by elastic means, such as springs, so as to obtain a corrector-actuating force which is proportional to the distance between the suspended and unsuspended parts of the vehicle as a function of the rigidity of the spring.
It can happen that springs produced in large series have a considerable spread of their characteristics, especially their rigidity, which has a direct influence on the functioning of the corrector. Thus, in some cases, the activation pressure of the corrector can be well beyond acceptable tolerance limits.
Because it is not feasible to machine a spring on an industrial scale, it is therefore necessary to adjust the rigidity of the spring or its conditions of use.
The French Pat. No. FR-A-2,534,208 makes known a braking corrector of the type recalled above, possessing means of calibration at the time of assembly of the vehicle. These calibration means consist of an auxiliary element located between one of the ends of the spring for connection to the unsuspended masses, and an element of the unsuspended masses. This auxiliary element consists of a bent lever which is articulated on the unsuspended element and of which one of the arms carries a log for the fastening of the spring and the other arm can be locked in position of the unsuspended element by means of a screw engaged into a slot made in this other arm.
This device has several disadvantages. First of all, it requires an intermediate piece, the fastening of which experiences tangential shearing forces and is therefore fragile. Moreover, it makes it possible only with difficulty to carry out a fine adjustment of the prestress exerted on the spring. Finally, the main disadvantage of this corrector is that the adjustment is made only after it has been installed on the vehicle, thus necessitating additional and complicated manipulations for the mechanic during the assembly of the vehicle.